The present invention relates to an isolation chamber, and particularly to an isolation chamber in which sterile and/or toxic materials are handled. More particularly, the present invention relates to an isolation chamber air curtain apparatus that functions to maintain a sterile environment in the isolation chamber when a leak develops in the isolation chamber.
During the manufacture of pharmaceutical products or other products, sterile and/or toxic materials are often placed in a decontaminated isolation chamber so that such materials can be handled by a worker properly. An unwanted leak in a material-handling system might lead to contamination of the isolation chamber and/or escape of material in the isolation chamber to the surroundings.
According to the present invention, an apparatus is provided for providing a clean working environment. The apparatus includes an isolation chamber sized to establish a working environment and bounded by a wall formed to include an access port communicating with the isolation chamber. The apparatus also includes an access device, such as a glove, mounted in the access port to enable a worker standing alongside an exterior surface of the wall to handle material in the isolation chamber through the access port without communicating air into the isolation chamber. A pressure generator, such as a motorized blower fan, is positioned to generate a pressure in the isolation chamber that is lower than the pressure of air along the exterior surface of the wall formed to include the access port. Air will be drawn from the surroundings into the isolation chamber through any air leak openings that develop in and around the access device so as to block outflow of air and materials in the isolation chamber through the air leak opening.
In preferred embodiments, an air curtain generator is arranged to discharge a filtered curtain of air pressurized to a level higher than the pressure of air in the isolation chamber so that the filtered curtain of air sweeps along and across the exterior surface of the wall formed to include the access port. If any air leak opening develops in the wall, access port, access device, etc., air from this pressurized curtain of air will flow into the isolation chamber through the air leak opening(s). A system is also provided for changing the "angle of attack" of the air flowing in the curtain of air relative to the exterior surface of the wall and for increasing the mass flow rate of air flowing in the curtain of air upon exposure of an air pressure sensor in the isolation chamber to an air pressure that is above a predetermined pressure level for a certain period of time.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.